Skip to main content

AMD Confirms Ryzen 7 5800X3D Is Not Overclockable

AMD
(Image credit: AMD)

AMD has confirmed that its upcoming Ryzen 7 5800X3D processor with a 96MB L3 cache aimed at gamers will not support overclocking. The official reason is that AMD's 3D V-Cache cannot really work at high voltages. That said, it remains to be seen for how long the CPU will work at its boost clocks.

"As people know, this is our first CPU with 3D V-Cache technology [...] and that packaging technology in our space has different voltage and frequency scaling than people may be accustomed with," said Robert Hallock, director of technical marketing at AMD, during a HotHardware broadcast (45:44). "On the desktop parts you've seen us ship parts that range up to 1.45V or even 1.5V in boost and that is not the limit for 3D V-Cache. The voltage limit on that is more like 1.3V to 1.35V." 

AMD has never listed the overclocking capability of its Ryzen 7 5800X3D processor, so it is not particularly surprising that the part does not support it. Meanwhile, this is the first time when AMD publicly acknowledges this, but 3D V-Cache voltage is a rather surprising reason. Initially, observers thought that because AMD installs its 3D V-Cache on top of Zen 3's 'built-in' L3 cache and then links them using through silicon vias (TSVs). This makes die surface non-uniform and to make it even, the company installs structural silicon spacers on top of Zen 3 general-purpose cores. These spacers trap some heat between the die, structural silicon, and integrated heat spreader. 

(Image credit: AMD)

Perhaps, structural silicon and its effect on heat dissipation adds to AMD's unwillingness to enable overclocking of its Ryzen 7 5800X3D part, but it looks like 3D V-Cache voltage range is the main reason. 

Cores | ThreadsL3 CacheP-Core Base/BoostTDP / PBP / MTP
Ryzen 7 5800X3D8P | 16 threads96MB3.4 / 4.5 GHz105W
Ryzen 7 5800X8P | 16 threads32MB3.8 / 4.7 GHz105W
Ryzen 9 5900X12P | 24 threads32MB3.7 / 4.8 GHz105W

In fact, to ensure stable operation of the CPU, AMD had to reduce base frequency of the Ryzen 7 5800X3D by 400MHz and boost clock by 200MHz when compared to the regular Ryzen 7 5800X, so overclocking might really be a bad idea of the processor. Good news is that AMD believes that the extra cache will not only compensate lower clocks, but will allow make the Ryzen 7 5800X3D part a better choice for gaming. Meanwhile, it should be noted that AMD stresses gaming performance, so 3D V-Cache may not be that efficient for other types of applications. 

"So, we are not going to allow CPU frequency overclocking or core voltage adjustment because out-of-the-box the design of the chip already uses ranges up to that voltage and frequency limit. On the other hand, fabric overclocking remains enabled, memory overclocking remains enabled, and we know that our parts get the most benefit from that anyway. […] We are working very hard to maximize our out-of-box performance for people and this is a very new thing we are trying."

Anton Shilov is a Freelance News Writer at Tom’s Hardware US. Over the past couple of decades, he has covered everything from CPUs and GPUs to supercomputers and from modern process technologies and latest fab tools to high-tech industry trends.

  • hotaru251
    So AMD pulled a MS.... "we tell you how to use it" mentality.

    let ppl have choice to do so.

    put a notice but still let ppl do it if they want.
    Reply
  • TerryLaze
    hotaru251 said:
    So AMD pulled a MS.... "we tell you how to use it" mentality.

    let ppl have choice to do so.

    put a notice but still let ppl do it if they want.
    No can do, the increase in rma would kill any profit from it.
    Reply
  • saunupe1911
    So would PBO automatically be disabled in the BIOS when this chip is installed?

    Does this chip require a special BIOS from MB manufacturers?

    If not then what's stopping someone from enabling PBO unless the chip just wouldn't take in the IO instructions.

    Oh nevermind...MB manufactures are rolling out AGESA 1.2.0.6b in their BIOS to support this.
    Reply
  • JeffreyP55
    Admin said:
    AMD's 3D V-Cache does not scale with high voltages.

    AMD Confirms Ryzen 7 5800X3D Is Not Overclockable : Read more
    I purchased a 5950x two weeks ago for 598 USD. If you feel the need to torture your already fast CPU. 5800 may have a slight advantage in games in its stock form..
    Reply
  • setx
    If overvoltages can easily kill new chips and they can't block only voltage control – it might be reasonable to disable overclocking.

    Motherboards just love to rise random voltages when they think you are "overclocking" if you didn't set pretty much all of them to fixed values. Better be safe than gain bad publicity from fried chips.

    Overall just one chip and even locked is quite sad for getting to know new technology.
    Reply
  • salgado18
    This sounds more and more like an experimental chip. If it does work well, we may see the tech in the next generation. If not, it will remain in history (and a few people's pcs).
    Reply
  • hotaru.hino
    salgado18 said:
    This sounds more and more like an experimental chip. If it does work well, we may see the tech in the next generation. If not, it will remain in history (and a few people's pcs).
    This makes a lot of sense to me. AMD's probably having a lull with their Zen 4 production and they really want to put this new technology in the field and seeing what works and whatnot.

    Similar to when NVIDIA made the GTX 750.

    TerryLaze said:
    No can do, the increase in rma would kill any profit from it.
    Well, using PBO voids the warranty.
    Reply
  • InvalidError
    hotaru.hino said:
    Well, using PBO voids the warranty.
    The worst part for AMD is that short of putting OTP fuses in the CPU that must be blown to enable PBO/OC/etc., AMD has no way of knowing what you have done with the chips. The easiest way to duck out of that is to ditch overclocking altogether.
    Reply
  • tennis2
    salgado18 said:
    This sounds more and more like an experimental chip. If it does work well, we may see the tech in the next generation. If not, it will remain in history (and a few people's pcs).
    With AM5 and Ryzen 6000(?) set to launch and of 2022, the window for changing architectural things now is little/none.

    I would agree that this smells like a guinea pig from AMD. Its likely/possible that it's a limitation of strapping Vcache to an architecture that wasn't explicitly designed for it. Whereas, Ryzen 6000 could have been designed around these voltage pitfalls (time will tell). But heck, if they can slap Vcache on previous-gen architecture to bide themselves a good stopgap "flagship" against Intel for the majority of 2022...why not!? Keep in mind, the 5800X3D probably won't draw much/any more power than the ~100W that the 5800X draws. Compare that to the 150-200W of the 12700K/12900K that it's competing against. Also, if the 5800X3D can beat or match the 12900KS while consuming nearly half the power, it will be a resounding win for AMD and an utter embarrassment for Intel.

    The 5800X3D still has a 4.5GHz boost frequency (5800X @ 4.7GHz). Which, based on their claim of 1.35V maximum and my own testing with my 5600G of 4.6GHz @ 1.44V single core and 4.0GHz @ 1.2V all core, seems respectable. I'd also hope/assume that AMD just caps voltage at 1.35V where someone could technically achieve a 4.5GHz all-core frequency. How much more does the average user want/need? Most reviews' overclocking results of Ryzen 5000 conclude with the recommendation that PBO and undervolting is at/near the best you can achieve without extreme cooling.
    Reply
  • hannibal
    For real v-cache cpus we have to wait Zen5 or Zen4+ or similar. This needs separate voltage controller for the cache and that can not be done afterwards. So any zen4 with same technology would suffer from same problem. But it can be done eventually, by making different voltage regulation to this part of the chip. So Zen4+ or Zen5 what ever comes after Zen4 could use vcache just nicely if it is sensible otherwise. Maybe adding more cache to the chip itself makes vcache obsolete?
    Reply